A quantum dot diaphragm is disclosed. The quantum dot diaphragm comprises a color gamut conversion region and a color gamut non-effective region surrounding the color gamut conversion region, wherein the color gamut non-effective region is provided with a quantum phosphor layer. According to the present disclosure, the color gamut non-effective region is provided with the quantum phosphor layer, so that the technical defect that an area of the diaphragm along the cutting line would become useless when the diaphragm is cut can be eliminated, and a color gamut conversion function of the quantum dot diaphragm can be further improved. The manufacturing procedure of the quantum dot diaphragm according to the present disclosure is simple. After the quantum dot diaphragm is cut, the color gamut non-effective region of the quantum dot diaphragm could be coated with the quantum phosphor, and then the quantum dot diaphragm needs to be assembled to the module product, so that the electronic products with high color gamut can be obtained.